Tissue Shaping Device

ABSTRACT

In one embodiment, the present invention relates to a tissue shaping device adapted to be disposed in a vessel near a patient&#39;s heart to reshape the patient&#39;s heart. Such tissue shaping device can include an expandable proximal anchor; a proximal anchor lock adapted to lock the proximal anchor in an expanded configuration; an expandable distal anchor; a distal anchor lock adapted to lock the distal anchor in an expanded configuration; and a connector disposed between the proximal anchor and the distal anchor, the connector having a substantially non-circular cross-section.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/275,630, filed Jan. 19, 2006, now U.S. Pat. No. 7,351,260; whichapplication is a continuation-in-part of pending U.S. patent applicationSer. No. 11/132,786, filed May 18, 2005; which application is acontinuation-in-part of application Ser. No. 10/066,426, filed Jan. 30,2002, now U.S. Pat. No. 6,976,995. Each of these applications isincorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

This invention relates generally to devices and methods for shapingtissue by deploying one or more devices in body lumens adjacent to thetissue. One particular application of the invention relates to atreatment for mitral valve regurgitation through deployment of a tissueshaping device in the patient's coronary sinus or great cardiac vein.

The mitral valve is a portion of the heart that is located between thechambers of the left atrium and the left ventricle. When the leftventricle contracts to pump blood throughout the body, the mitral valvecloses to prevent the blood being pumped back into the left atrium. Insome patients, whether due to genetic malformation, disease or injury,the mitral valve fails to close properly causing a condition known asregurgitation, whereby blood is pumped into the atrium upon eachcontraction of the heart muscle. Regurgitation is a serious, oftenrapidly deteriorating, condition that reduces circulatory efficiency andmust be corrected.

Two of the more common techniques for restoring the function of adamaged mitral valve are to surgically replace the valve with amechanical valve or to suture a flexible ring around the valve tosupport it. Each of these procedures is highly invasive because accessto the heart is obtained through an opening in the patient's chest.Patients with mitral valve regurgitation are often relatively frailthereby increasing the risks associated with such an operation.

One less invasive approach for aiding the closure of the mitral valveinvolves the placement of a tissue shaping device in the cardiac sinus,a vessel that passes adjacent the mitral valve annulus. (As used herein,“coronary sinus” refers to not only the coronary sinus itself, but alsoto the venous system associated with the coronary sinus, including thegreat cardiac vein.) The tissue shaping device is designed to reshapethe vessel and surrounding valve tissue to reshape the valve annulus andother components, thereby promoting valve leaflet coaptation. Thistechnique has the advantage over other methods of mitral valve repairbecause it can be performed percutaneously without opening the chestwall. Examples of such devices are shown in U.S. patent application Ser.No. 10/142,637, “Body Lumen Device Anchor, Device and Assembly” filedMay 8, 2002; U.S. patent application Ser. No. 10/331,143, “System andMethod to Effect the Mitral Valve Annulus of a Heart” filed Dec. 26,2002; U.S. patent application Ser. No. 10/429,172, “Device and Methodfor Modifying the Shape of a Body Organ,” filed May 2, 2003; and U.S.application Ser. No. 10/742,600 filed Dec. 19, 2003.

SUMMARY OF THE INVENTION

Tissue shaping devices can encounter material stress while in storage,during deployment and after implant. Repeated stress can lead tomaterial fatigue and breakage. The present invention provides a tissueshaping device with improved stress response characteristics.

One aspect of the invention provides a tissue shaping device adapted tobe disposed in a vessel near a patient's heart to reshape the patient'sheart. The tissue shaping device has an expandable proximal anchor; aproximal anchor lock adapted to lock the proximal anchor in an expandedconfiguration; an expandable distal anchor; a distal anchor lock adaptedto lock the distal anchor in an expanded configuration; and a connectordisposed between the proximal anchor and the distal anchor, with theconnector having a substantially non-circular cross-section, such as asubstantially rectangular or substantially oval cross-section.

In some embodiments, the distal anchor lock includes a bend in theconnector and, optionally, a compliant element adjacent the bend in theconnector, with at least the compliant element being adapted to changeshape during a distal anchor locking operation. In some embodiments thedistal anchor lock has an anchor lock element adapted to move withrespect to the connector as the distal anchor expands.

In some embodiments, the connector is a first connector, and the devicealso has a second connector extending between the proximal and distalanchors. The distal anchor lock may make up at least part of the wireelement. The second connector can be adapted to provide fatigueresistance.

In some embodiments, the distal anchor has a crimp and a wire elementextending from the crimp, the wire element having a strain reliefportion extending distal of the crimp to form a bend extendingsubstantially below a plane defined by the crimp. The distal anchor wireelement may also have a vessel engagement portion extending proximallyfrom the strain relief portion and away from the crimp and a lockportion extending from the vessel engagement portion to form part of thedistal lock.

In further embodiments, proximal anchor can include a crimp and a wireelement extending from the crimp, with the wire element having a strainrelief portion extending distal of the crimp to form a bend extendingsubstantially below a plane defined by the crimp. The proximal anchorwire element further may also have a vessel engagement portion extendingproximally from the strain relief portion and away from the crimp and alock portion extending from the vessel engagement portion and formingpart of the proximal lock.

Another aspect of the invention provides a tissue shaping device adaptedto be disposed in a vessel near a patient's heart to reshape thepatient's heart. The tissue shaping device may include an expandableproximal anchor, with the proximal anchor having a crimp and a wireelement extending from the crimp and the wire element having a strainrelief portion extending distal of the crimp to form a bend extendingsubstantially below a plane defined by the crimp. The tissue shapingdevice may also have an expandable distal anchor, with the distal anchorcomprising a crimp and a wire element extending from the crimp and thewire element having a strain relief portion extending distal of thecrimp to form a bend extending substantially below a plane defined bythe crimp. The tissue shaping device may also have a connector extendingbetween the proximal anchor crimp and the distal anchor connector crimp.

In some embodiments, the proximal anchor wire element further includes avessel engagement portion extending proximally from the strain reliefportion and away from the crimp, a vessel engagement portion extendingproximally from the strain relief portion and away from the crimp, aproximal anchor lock adapted to lock the proximal anchor in an expandedconfiguration, and/or a distal anchor lock adapted to lock the distalanchor in an expanded configuration.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 is a schematic view of a human heart with the atria removed.

FIG. 2 is a schematic view of a human heart showing the deployment of atissue shaping device in the coronary sinus.

FIG. 3 is a perspective view of a tissue shaping device according to oneembodiment of this invention.

FIG. 4 is another perspective view of the tissue shaping device of FIG.3.

FIG. 5 is side elevational view of the tissue shaping device of FIGS. 3and 4.

FIG. 6 is a perspective view showing the device of FIG. 3 in anunexpanded configuration and in a partially expanded configuration.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1, is a superior view of a heart 100 with the atria removed. Aspictured, the heart comprises several valves including mitral valve 102,pulmonary valve 104, aortic valve 106 and tricuspid valve 108. Mitralvalve 102 includes anterior cusp 110, posterior cusp 112 and annulus114. Annulus 114 encircles cusps 110 and 112 and functions to maintaintheir respective spacing to ensure complete mitral valve closure duringleft ventricular contractions of the heart 100. As illustrated, coronarysinus 116 partially encircles mitral valve 102 and is adjacent to mitralvalve annulus 114. Coronary sinus 116 is part of the venous system ofheart 100 and extends along the AV groove between the left atrium andthe left ventricle. This places coronary sinus 116 essentially withinthe same plane as mitral valve annulus 114, making coronary sinus 116available for placement of shaping device 200 in order to effect mitralvalve geometry and to restore proper valve function.

FIG. 2 illustrates one possible embodiment of an implantable shapingdevice 200, which is deployable in coronary sinus 116 or other bodylumen. As illustrated in FIG. 2, device 200 generally comprises anelongated connector 220 disposed between a distal anchor 240 and aproximal anchor 260. Both distal anchor 240 and proximal anchor 260 areshown in their deployed (i.e. expanded) configuration in FIG. 2,securely positioned within the coronary sinus 116. FIG. 2 furtherdepicts, in phantom, a deployment system 300 comprising catheter 302 fordelivering and positioning shaping device 200 in the coronary sinus 116.Further details of the delivery system may be found in U.S. patentapplication Ser. Nos. 10/946,332 and 10/945,855.

FIGS. 3-5 show one embodiment of a tissue shaping device 400 withproximal anchor 402 and distal anchor 404 in their expanded and lockedconfigurations. In this embodiment, proximal anchor 402 is made from ashape memory metal wire 405 (such as Nitinol) extending from a crimp406. Stress relief portions 408 of the wire extend distal to crimp 406;the purpose of these stress relief features will be discussed below withreference to FIG. 6. Wire 405 extends upward from stress relief portions408 to form vessel engagement portions 410 which cross to form a FIG. 8pattern, as shown. Vessel engagement portions 410 and crimp 406 engagethe inner wall of the coronary sinus or other vessel in which the deviceis implanted. Wire 405 also forms a lock loop 412 which interacts withan arrowhead-shaped element 414 extending from the proximal end of thecrimp to form the proximal anchor lock. Actuation of the proximal anchorlock is described in U.S. patent application Ser. Nos. 10/946,332 and10/945,855.

Likewise, distal anchor is made from a shape memory wire 416 extendingfrom a crimp 418. Stress relief portions 420 of the wire extend distalto crimp 418. Wire 416 extends upward from stress relief portions 420 toform vessel engagement portions 422 which cross to form a FIG. 8pattern, as shown. Vessel engagement portions 422 and crimp 418 engagethe inner wall of the coronary sinus or other vessel in which the deviceis implanted. Wire 416 also forms a lock loop 424.

Extending between anchors 402 and 404 are a substantially flat connector426 and a wire connector 428. In this embodiment, connectors 426 and 428are both made of shape memory metal, such as Nitinol. When device 400 isdeployed within the coronary sinus or other vessel, the distal anchor404 is deployed from the delivery catheter first, then expanded andlocked to maintain its position within the vessel. A proximal cinchingforce is then applied on the distal anchor from, e.g., a tether attachedto arrowhead element 414 until an appropriate amount of reshaping of themitral valve or other tissue has occurred (as determined, e.g., byviewing blood flow with fluoroscopy, ultrasound, etc.). Whilemaintaining the cinching force, proximal anchor 402 is deployed from thedelivery catheter, expanded and locked in the expanded configuration.The device 400 may then be released from the delivery system's tether.By spanning the distance between proximal anchor 402 and distal anchor404, connectors 426 and 428 maintain the reshaping force on the tissue.

When deployed in the coronary sinus to reshape the mitral valve annulus,the tissue shaping devices of this invention are subjected to cyclicbending and tensile loading as the patient's heart beats. Device 400differs from prior tissue shaping devices by changing thecross-sectional profile of the connector, in this illustration by makingconnector 426 substantially flat. This shape provides improved fatigueresistance over prior devices whose wire connectors had a round profile.In addition, the flat shape of connector 426 helps device 400 to orientitself within the vessel during the deployment process. In alternativeembodiments, connector 426 may have a more round shape, with, e.g., anoval cross-section or other non-circular cross-section instead of arectangular cross-section.

Prior to use, tissue shaping devices such as those shown in FIGS. 3-5may be stored in cartridges or other containers, such as described inU.S. patent application Ser. Nos. 10/946,332 and 10/945,855, thendelivered to the coronary sinus or other vessel in a delivery catheter,as shown in FIG. 2. During storage and delivery, the device may becompressed in the directions shown by the arrows in FIG. 6 from anunstressed expanded shape into an unexpanded configuration, such as theconfiguration shown in phantom in FIG. 6. There are two aspects ofstresses experienced by device. In one aspect stress may be impartedwhile device is collapsed for storage and delivery. While collapsed itis possible that the change of shape from unstressed configuration tocollapsed condition creates an area of higher stress, Anchor wire formsare designed with stress reliving element (420) to reduce this type ofstress on implant while in storage or during deployment. Another aspectof stress on implant happens when it is deployed, locked and detachedfrom delivery catheter. This type of stress comes from the repeatedmotion (fatigue) of heart increasing bending stress on implant. Thiscould result in implant fracture. The connector element design (426)with flat ribbon provides resistance to this bending stress thusreducing chances of fatigue fracture. In this embodiment, therefore, thedevice is provided with stress relief features. Bent portions 408 ofproximal anchor wire 405 provide extra stress relief while the device isin storage and relieves material stress on the wire that would otherwisebe present where wire 405 emerges from crimp 406. Similar stress reliefbends 420 in distal anchor wire 416 serve a similar function.

FIG. 6 shows device 400 in a compressed storage configuration (shown inphantom) and in a partially expanded but not yet locked configuration.After emerging from the delivery catheter, the shape memorycharacteristics of anchors 402 and 404 will cause them to expand to,e.g., the configuration shown in solid line in FIG. 6. After the userconfirms that the device is in the desired position, the user may thenemploy the device delivery system (such as that described in U.S. patentapplication Ser. Nos. 10/946,332 and 10/945,855) to lock the distalanchor by moving lock loop 424 distally with respect to the connector.Distal movement of lock loop 424 beyond the position shown in FIG. 6will cause bent portions 430 and 432 of connectors 426 and 428,respectively, to move toward each other, permitting lock loop to passover them to the position shown in FIG. 1, thereby locking the distalanchor in an expanded configuration. After placement of the proximalanchor in its desired position (after, e.g., application of a proximallydirected cinching force), proximal anchor lock loop 412 may be advanceddistally over arrowhead element 414 to lock the proximal anchor in anexpanded configuration.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

1. A tissue shaping device adapted to be disposed in a vessel near apatient's heart to reshape the patient's heart, the tissue shapingdevice comprising: an expandable proximal anchor; a proximal anchor lockadapted to lock the proximal anchor in an expanded configuration; anexpandable distal anchor; a distal anchor lock adapted to lock thedistal anchor in an expanded configuration; and a connector disposedbetween the proximal anchor and the distal anchor, the connector havinga substantially non-circular cross-section.
 2. The device of claim 1wherein the connector flat element has a substantially rectangularcross-section.
 3. The device of claim 1 wherein the distal anchor lockcomprises a bend in the connector.
 4. The device of claim 3 wherein thedistal anchor lock further comprises a compliant element adjacent thebend in the connector, the compliant element being adapted to changeshape during a distal anchor locking operation.
 5. The device of claim 1wherein the distal anchor lock comprises an anchor lock element adaptedto move with respect to the connector as the distal anchor expands. 6.The device of claim 1 wherein the connector comprises a first connector,the device further comprising a second connector extending between theproximal and distal anchors.
 7. The device of claim 6 wherein the distalanchor lock comprises at least part of the second connector.
 8. Thedevice of claim 1 wherein the distal anchor comprises a crimp and a wireelement extending from the crimp, the wire element having a strainrelief portion extending distal of the crimp to form a bend extendingsubstantially below a plane defined by the crimp.
 9. The device of claim8 wherein the distal anchor wire element further comprises a vesselengagement portion extending proximally from the strain relief portionand away from the crimp.
 10. The device of claim 9 wherein the distalanchor wire element further comprises a lock portion extending from thevessel engagement portion and forming part of the distal lock.
 11. Thedevice of claim 1 wherein the proximal anchor comprises a crimp and awire element extending from the crimp, the wire element having a strainrelief portion extending distal of the crimp to form a bend extendingsubstantially below a plane defined by the crimp.
 12. The device ofclaim 11 wherein the proximal anchor wire element further comprises avessel engagement portion extending proximally from the strain reliefportion and away from the crimp.
 13. The device of claim 12 wherein theproximal anchor wire element further comprises a lock portion extendingfrom the vessel engagement portion and forming part of the proximallock.
 14. A tissue shaping device adapted to be disposed in a vesselnear a patient's heart to reshape the patient's heart, the tissueshaping device comprising; an expandable proximal anchor, the proximalanchor comprising a crimp and a wire element extending from the crimp,the wire element having a strain relief portion extending distal of thecrimp to form a bend extending substantially below a plane defined bythe crimp; an expandable distal anchor, the distal anchor comprising acrimp and a wire element extending from the crimp, the wire elementhaving a strain relief portion extending distal of the crimp to form abend extending substantially below a plane defined by the crimp; and aconnector extending between the proximal anchor crimp and the distalanchor connector crimp.
 15. The device of claim 14 wherein the proximalanchor wire element further comprises a vessel engagement portionextending proximally from the strain relief portion and away from thecrimp.
 16. The device of claim 14 wherein the distal anchor wire elementfurther comprises a vessel engagement portion extending proximally fromthe strain relief portion and away from the crimp.
 17. The device ofclaim 14 further comprising a proximal anchor lock adapted to lock theproximal anchor in an expanded configuration.
 18. The device of claim 14further comprising a distal anchor lock adapted to lock the distalanchor in an expanded configuration.
 19. The device of claim 6 whereinsaid second connector is adapted to provide fatigue resistance.